Resiliency Framework for Seismic Risk Assessment and Management of Buildings

加拿大保险局(IBC)估计，地震对西部(不列颠哥伦比亚省)和东部(渥太华-蒙特利尔-魁北克市走廊)核心公共基础设施(CPI)造成的破坏约为600-750亿美元。IBC的报告进一步强调，随着弹性的纳入，损害可以显著减少。系统的地震恢复力一直与减少机会、吸收和在地震后迅速恢复有关。CPI，包括道路、桥梁、交通、供水和废水系统，对于确保加拿大的健康、安全、经济安全和整体生活质量至关重要。这项研究计划的长期目标是为加拿大的CPI制定一个弹性框架。该框架将包含每个CPI的失败以及依赖和级联效应。此外，该框架将纳入多种地震，例如主震-余震。 在这项建议中，弹性框架应用于加拿大不同的建筑类型，重点是通过量化市中心在失败后的后果来减少地震的影响和提高恢复能力。为了实现这一目标，研究目标分为以下三个主题： 主题A)通过考虑不同的不确定性和建筑不规则性，为现有建筑制定建筑脆弱性评估和坚固指数框架(项目A1和A2)。根据现有的信息水平，将制定一份纳入模型选择和分析技术的建筑物脆弱性评估准则。最后，将制定一项新的加拿大建筑规范有效性分级协议，并将其应用于加拿大600多个城市(按照建筑规范的规定)。 主题B)制定一个综合的翻新优化和选择框架。这一框架将使决策者能够对不同的改装备选方案进行情景分析，并选择所需的改装技术(项目B1、B2和B3)。改造资源的分配和优化将在两个不同的分辨率(城市和建筑级别)下进行，并涉及对不同危险级别的模拟。在这项研究中，将使用一种保证最优性的免导数方法。由于与危险评估相关的不确定性和对特定替代品决策过程的了解，决策的挑战进一步加剧。 主题C)制定一个框架，在风险评估和管理框架内量化结构性和非结构性故障。该框架将通过故障树说明故障的可能性，并通过事件树分析说明故障的后果。在风险文献中，这被表示为领结图。因此，主题A中的建筑脆弱性工具和主题B中的翻新评估框架将被整合到这个蝴蝶结图表中。停机时间将被量化为故障的后果之一，该故障涉及恢复能力框架的快速恢复部分(项目C1)。 这项研究将导致对地震风险评估的深入了解，并显著改善对民用基础设施系统的管理。从这项关键研究中获得的知识和理解将直接改善现有建筑物的风险评估和管理。这将通过提高我们民用基础设施系统的弹性，对加拿大社会产生重大影响。

The Insurance Bureau of Canada (IBC) estimation of earthquake induced damage to core public infrastructure (CPI) in western (British Columbia) and eastern (Ottawa-Montreal-Quebec City corridor) is in the order of $60-$75 billion. The IBC’s report further highlighted that with the incorporation of resiliency, the damage can significantly be reduced. Seismic resiliency of a system has been associated with reducing chances, absorbing and recovering quickly after a shock. CPI, including roads, bridges, transit, and water and wastewater systems, are essential to ensure health, safety, economic security and overall quality of life in Canada. The long term objective of this research program is to develop a resiliency framework for Canada’s CPI. The framework will incorporate the failure of each CPI and also dependencies and cascading effects. Furthermore, the framework will incorporate multiple shocks, e.g. mainshock-aftershock earthquakes. In this proposal, the resiliency framework is applied for different Canadian building types, with focus on reducing impact of an earthquake and improving the recovery by quantifying the downtown in the consequence of failure. To achieve this objective, the research goals are categorized into the following three themes: Theme A) Develop building vulnerability assessment and robustness index framework for existing buildings by accounting for different uncertainties and building irregularities (Projects A1 and A2). Based on the level of information available a building vulnerability assessment guidelines that incorporate model selection and analysis technique will be developed. Finally, a new Canadian Building Code Effectiveness Grading protocol will be developed and applied to over 600 Canadian cities (as provided in the building code). Theme B) Develop an integrated retrofit optimization and selection framework. This framework will enable the decision makers to carry out scenario analysis for different retrofit alternatives and select the desired retrofitting technique (projects B1, B2 and B3). The retrofit resource allocation and optimization will be undertaken at two different resolutions (city and building levels) and involve simulations for different hazard levels. In this research, a derivative-free approach that guarantee of optimality will be used. The challenge of decision making is further compounded due to the uncertainties associated with hazard assessment and knowledge of the decision making process for specific alternatives. Theme C) Develop a framework that will quantify both structural and non-structural failures within the risk assessment and management framework. This framework will account for the likelihood of failure through fault-tree and consequence of failure through event-tree analyses. This is denoted as a bow-tie diagram in the risk literature. Thus, the building vulnerability tool from Theme A and retrofitting assessment framework from Theme B will be integrated into this bow-tie diagram. Downtime will be quantified as one of the consequence of failure that addresses the recover quickly component of the resiliency framework (project C1). This research will lead to an advanced understanding of seismic risk assessment and significantly better management of civil infrastructure systems. The knowledge and understanding gained from this critical research will directly improve the risk assessment and management of existing buildings. This will have significant impact on Canadian society by improving the resiliency of our civil infrastructure systems.